Some of conventional one-way clutches have, in Japanese Patent Application Laid-Open Publication No. H09-014302 for example, a so-called single cage type structure that includes a single cage (retainer) for retaining a plurality of sprags. Another one-way clutch configured by modifying the single cage type improves meshing performance of the one-way clutch to further solidify integration of the retainer and an outer race by providing notches or cuts in a flange portion of the retainer to give, as in Japanese Patent Application Laid-Open Publication No. H10-009291 for example, elasticity to the retainer.
FIG. 3A is a schematic outline view illustrating a state of a conventional one-way clutch 101 described in Japanese Patent Application Laid-Open Publication No. H10-009291 as viewed from one side in an axial direction; FIG. 3B is a sectional view taken along an arrow line b-b in FIG. 3A; and FIG. 3C is a schematic outline view illustrating a state of the one-way clutch 101 as viewed from the other side in the axial direction. Note that FIGS. 3A, 3B and 3C omit illustrations of an inner race and an outer race.
As illustrated in FIGS. 3A, 3B and 3C, the conventional one-way clutch 101 includes: a plurality of cams 107 serving to transfer a torque to between an inner race 103 (see FIGS. 4A and 4B) and an outer race 105 (see FIGS. 4 A and 4B); a ring-shaped retainer 109 retaining the plurality of cams 107 at a predetermined interval in a circumferential direction; and a spring member 115 biasing the plurality of cams 107 in such a direction as to come into contact with an outer peripheral surface 111 of the inner race 103 and an inner peripheral surface 113 of the outer race 105 in a torque non-transfer state. The retainer 109 is configured to include a cylindrical portion 121 disposed between the inner race outer peripheral surface 111 and the outer race inner peripheral surface 113, and a flange portion 123 formed at one end of the cylindrical portion 121, and the cylindrical portion 121 is provided with a plurality of windows 125 for retaining the cams 107 in a swingable manner. The cams 107 are fitted in these windows 125 in one-to-one correspondence.